Adding radiators to radiant system

We bought a 2700 Sq ft log house that has radiant heat in the daylight basement, pellet stove upstairs. It has a boiler upstairs with separate circuits for the closed radiant heat and the domestic taps. The upstairs master is at the opposite end of the house from the pellet stove, and running electric heaters is a little expensive.
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What I'm wondering is whether I could install a couple of radiators upstairs (in master bed and bath) fed by pex from the manifold. From the layout, I'd have to rip a lot of drywall, but it could be done.